1. Field of the Invention
The present invention relates to a device for adjusting lateral position of a chair armrest in response to the size of the user.
2. Description of the Related Art
FIGS. 7 and 8 of the drawings illustrate a conventional device for adjusting lateral position of a chair armrest. The adjusting device includes an armrest with an extension 21xe2x80x2, a press member 22xe2x80x2 pivotally mounted to the extension 21xe2x80x2 by a pin 211xe2x80x2 and having a first end with a protrusion 222xe2x80x2 and a second press end 221xe2x80x2, an outer sleeve 23xe2x80x2, and an inner sleeve 24xe2x80x2 that is mounted in the outer sleeve 23xe2x80x2. The inner sleeve 24xe2x80x2 and the outer sleeve 23xe2x80x2 are secured to an underside of a seat 3xe2x80x2. The outer sleeve 23xe2x80x2 has an elongated hole 232xe2x80x2 and the inner sleeve 24xe2x80x2 includes a plurality of consecutive positioning holes 244xe2x80x2, wherein each two adjacent positioning holes 244xe2x80x2 are connected by a neck portion (not labeled). As illustrated in FIG. 8, the press member 22xe2x80x2 is biased by a spring 212xe2x80x2 such that the protrusion 222xe2x80x2 is extended through the elongated hole 232xe2x80x2 and engaged with one of the positioning holes 244xe2x80x2. When adjustment of lateral position of the armrest is required, the press end 221xe2x80x2 is pressed to overcome the spring force causing the protrusion 222xe2x80x2 to be disengaged from the positioning hole 244xe2x80x2. The armrest is then moved laterally relative to the seat 3xe2x80x2 to a desired position, and the press end 221xe2x80x2 is then released to cause the protrusion 222xe2x80x2 to engage with an associated positioning hole 244xe2x80x2.
However, the inner sleeve 24xe2x80x2 must be fittingly engaged in the outer sleeve 23xe2x80x2 and this requires high-precision processing. In addition, it is found that the protrusion 222xe2x80x2 cannot be smoothly guided into the positioning hole 244xe2x80x2. Furthermore, engagement of the protrusion 222xe2x80x2 with the positioning hole 244xe2x80x2 is not reliable such that the whole armrest extension 21xe2x80x2 might be completely disengaged from the sleeves 23xe2x80x2 and 24xe2x80x2 when a relatively large force is applied to move the armrest extension 21xe2x80x2 outward. The user might thus be injured.
It is the primary object of the present invention to provide an improved device for adjusting lateral position of a chair armrest in response to the size of the user, wherein the armrest is reliably retained in place after adjustment in a lateral position thereof.
In accordance with one aspect of the invention, a device for adjusting lateral position of an armrest of a chair relative to a seat of the chair comprises:
a base securely attached to a seat of a chair, the base including a plurality of positioning holes;
an extension extended from an armrest of the chair, the extension being slidably received in the base and slidable in a lateral direction relative to the seat;
a positioning member including an intermediate portion pivotally attached to the extension, a first operative end, and a second end releasably engaged with at least one of the positioning holes, and
means for preventing disengagement of the extension from the base during sliding movement of the extension relative to the seat.
The extension includes an opening and the second end of the positioning member includes two protrusions that are extended through the opening and releasably engaged with two of the positioning holes of the base. The base includes a screw hole. The positioning member includes a recessed area in an intermediate portion of an underside thereof, the recessed area having a through-hole. A mounting member is mounted to the recessed area of the positioning member and has a stub extended through the through-hole. A bolt is extended through the stub and engaged with the screw hole, thereby pivotally mounting the positioning member between the extension and the mounting member. The extension further includes at least one engaging hole, and the mounting member includes at least one peg for engaging with the engaging hole. An elastic element has a coil portion mounted around the stub of the mounting member, a first leg attached to the positioning member, and a second leg attached to the mounting member.
In an embodiment of the invention, the extension includes two engaging holes. The mounting member includes two lateral walls each having a peg for engaging with an associated engaging hole. An elastic element has a coil portion mounted around the stub of the mounting member, a first leg attached to one of the lateral wall of the positioning member, and a second leg attached to the mounting member.
The preventing means includes a screw hole defined in the extension, a screw engaged with the screw hole, and a stop formed on the base for engaging with the screw when the extension is moved to an outmost position relative to the seat of the chair. Preferably, each positioning hole of the base includes two lateral guiding sides for guiding the protrusions of the positioning member.
In accordance with a second aspect of the invention, a device for adjusting lateral position of an armrest of a chair relative to a seat of the chair comprises:
a base securely attached to a seat of a chair, the base including a plurality of positioning holes;
an extension extended from an armrest of the chair, the extension being slidably received in the base and slidable in a lateral direction relative to the seat;
a positioning member including an intermediate portion pivotally attached to the extension, a first operative end, and a second end releasably engaged with at least one of the positioning holes, the positioning member further including an underside and a through-hole in an intermediate portion thereof;
a mounting member mounted to the underside of the positioning member and having a stub extended through the through-hole;
a bolt extended through the stub and engaged with the extension, thereby pivotally mounting the positioning member between the extension and the mounting member.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.